March 12, 2015

When it comes to service delivery, the TransLink narrative goes like this:

Delivered transit service hours have fallen behind the population growth since 2010 reaching levels last in 2008. That is leading to more crowding, more pass-ups and a worsening of the overall transit experience [1][18].

The graph presented to support this thesis is usually a truncated version of the below one:

A problem with this narrative using the total service hours delivered by the TransLink subsidiaries and contractors is that it magnifies the 2010 peak, by including service provided for the Olympic Games. A second issue is that it includes the technical services which could vary greatly without affecting the transit supply. Below is an example of such differences [2]:

route

Revenue hour service

Total hour service

difference in %

All

3,841,860

4,950,000

29%

555

13,500

21,400

60%

96B

42,900

62,400

44%

.

Revenue service or service supply means service dedicated to move transit passengers (passenger can use the provided service).
Total service is the revenue service + technical service (deadhead run, layover…).
That is matching the APTA definitions. Translink’s reports tend to easily interchange the both terms.

The relatively important difference between the total service and the effective revenue service had already been noticed as an optimization avenue by the 2012 TransLink commissioner’s review [17]. The more fundamental issue is that the service/hour provided is not representative of the Transit supply:

The replacement of a 40 foot bus by a 60 foot bus wouldn’t increase the service hours per capita, but it could address overcrowding.

Faster bus routes infer less hours of service but are improving the service offer.

The replacement of a bus route by a rail one, offering much faster and higher capacity vehicles, can both address crowding while improving the offer, while resulting in a decrease in total service hours.

Seat.Kilometres Supply

The seat.km metric; which needs to be understood as (seat+standee).km in the transit world; is a much better way to evaluate the transit supply, and for this reason is widely used in the passenger transportation industry.

As an example: 1 hour of coach service on the express route 555 using the Hwy 1 HOV lane can provide ~3600 seat.km when one hour of C23 Shuttle bus in Vancouver’s Yaletown, provides only ~320 seat.km. Differences in average speed and vehicle capacity drastically affect the offered service which is reflected by the seat.km metric:

The effect of the introduction of the Canada line service in late 2009 is clear. Though service hours may have stayed stable since 2011, the seat.km supply has slightly increased thanks to a greater use of articulated buses. The advent of routes 96B and 555, having higher speed than average, also provides more seat.km at constant service hours. Is this enough to keep pace with the population growth?

The point is moot. If a downtrend can be observed since 2011, we are nowhere near the 2008 level. The introduction of rapid transit lines tends to exhibit a positive long term trend.

Canadian and International Comparisons

To provide a larger perspective, the Vancouver transit supply is compared to other Canadian metropolitan areas, using numbers as provided by the Transportation Association of Canada [4]. The Vancouver numbers have been normalized to correlate with those provided by the association [5] . Vancouver tends to exhibit favorable trends when compared to its Canadian peers:

Vancouver pales when compared to Megalopolises such as Paris, London or Hong Kong [6], but its Transit supply is much greater than in Portland and comparable to the ones of European metropolises of population size closer to Metro Vancouver, such as Lille or Lyon [7]. Nevertheless, this comes with one caveat: both Lille and Lyon are fed by an important suburban train network which has not been accounted for in the following figure:

The above international comparison is assuming 4 standees per m2 to estimate the vehicle capacity [9]:

The occupancy rate [14] can be a good proxy to assess the relevance of the supply: the higher the occupancy rate is, the more likely crowding issues will arise. On the other hand, a low occupancy rate could suggest an excess of capacity.

Crowding experienced locally with a low occupancy rate could suggest that the transit supply deployment is not optimal, but some other issues could arise: A directional demand unbalance makes crowding difficult to address without deploying excess capacity on the underused direction.

Possibly a transit world specific: even the busiest systems don’t achieve an occupancy rate greater than 30%. In that light, the TransLink system appears to be a heavily used one.

It is worthwhile to note that TransLink estimates the average transit trip length at ~8km [15] when TfL estimates the average bus trip length at 3.5km and the Underground trip length at 8km [16]. Similarly the average bus or tram trip length is 3.3km and the subway trip length 5km in Paris. The reliability of trip length data could be an issue but a consequence of longer trips in Vancouver is that TransLink needs to provide more seat.km per trip than London or Paris.

(*) This article has been first published in the December 2014 newsletter from Transport Action BC.

[2] Difference between the GTFS data (revenue hr) and the Translink 2013 Annual report (Total service hr). see more in this post

[3] Supply is computed on the first Friday following Labour Day (usually one of the busiest Transit days of the year) of each year from GTFS schedule and fleet deployment observations. The vehicles’ capacity used are the maximum as displayed on the concerned vehicles. see more in this post

[5] Numbers otherwise differ, possibly due to different assumptions, such as on the vehicles’ capacity. The urban areas, used by the association [4], don’t match either the area covered by the transport agencies, so numbers are subject to caution.

[9] Agencies could have different standards (e.g. 6 persons per sqm in Hong Kong). The vehicle capacity is per bus or consist (train) unless otherwise specified. When different vehicle types are used, a vehicle revenue.km weighted average is used.

[10] The capacity is per car. Hong Kong Tram capacity is 125, and Hong Kong Airport train capacity is 120 per car.

May 21, 2013

…or perceived safety and objective safety of the cycle tracks

A study on Toronto and Vancouver (Canada) from [4]: the risk of bike infrastructure separated of traffic is under-estimated. Note the result carried for the cycle track is an aberrant and irrelevant one for reason explained in [8]

Usually, Urban segregated bike lanes (cycle tracsk) are perceived as safer than non segregated one, by many cycle advocates and public alike. Alas most accident statistics say otherwise, and most scientific studies conclude, consistently overtime, that segregated bike lanes impair safety by ~20% ([1] summarizes and complete previous studies, see also a list of studies at [9]), some older studies putting this number up to 4 time higher [2].

Of course, it is possible to find some studies saying otherwise, but usually those studies show significant methodology shortcomings. To focus only on recent Canada centric examples: [5] draws conclusion on cycle track from a field study conducted in cities not having such infrastructure per sei, as seen in [8] and obvious selction biais discredit results from [3] (more critics here and there):

Montreal, QC: In (3), a separate bike path in a one lane residential street (rue Brebeuf) is compared to an up to 6 lanes thoroughfare (rue st Denis) on a 1km section (Rachel to Laurier), where St Denis has more intersection, and higher speed limit than Brebeuf...to conclude that separates bike lane improve cyclist safety! (no indication of motor traffic volume is provided) -

The most recent study extended to the USA by the same authors, [10], seems to suffer similar flaws [11].

In urban area, most of the cyclist accidents are due to conflict with motor vehicles (85% in French cities according to the OSNIR), and most of them occur at intersection: In Canadian cities, 50% of fatal accidents and 72% of accidents resulting in serious injury occurred at intersections [12].

Thought, that a separated bike lane can remove potential conflicts along a road, and is recognized to reduce risk in such cases, it makes matter worse at intersections: This is mainly due to the fact cyclists, not on the road, tend to be overlooked by other road users, generating conflict at road intersections. The increased risk for cyclist is illustrated below:

According to (2), the cyclist could be up to 12 time safer on the right side of the street - credit photo (6)

Aware of this fact, Some transportation professional organizations don’t recommend separated bike lane: it is the case for the AASHTO in the USA, or the CERTU for urban area in France. A position supported by numeorus cyclist organizations, be in France (FFCT, Fubicy) or Germany (ADFC), which have been at best rather neutral on the development of segregated cycle track, in some case opposed, and consistently advocating against the mandatory use of it. That eventually became the case for most of the french cycle track, circa 2000. For this later purpose a new road sign has been introduced, and Germany is following track:

The cycle in a blue square sign has been introduced circa 2000: it indicates a recommended cycle track. The cycle in a blue disc indicate a mandatory cycle track ... except of course in UK Which has not ratified the Vienna convention on road sign, from which those signs are derived

An issue is that motorists tend to ignore the difference, and harass cyclists not using the cycle tracks

Traffic engineers, on their side, sometimes eager to remove cyclist of the road for their “good”, have worked to increase the safety of separate bike lane:

Reintroduction into general traffic at intersection

Rennes, France (Armorique Bld): Cycle track merging in general traffic at intersection, and resuming after it

Treating cyclist as pedestrian at intersection

Hong Kong (Along Ting Kok Rd, Kong Kong NT): Cyclists are expected to walk their bikes to the cycle track... and dismount at every intersections...what by the way is seldom respected in despite of the British style staggered pedestrian crossing! -credit photo left (16), right, Google

Cycling Commuters are generally not impressed by those treatments, which are just slowing down their commute, even when the obligation to walk the bike at intersections (Hong Kong case), is obviously widely disregarded by cyclists using such facilities.

It has been “invented” in Copenhagen in 1981: The basic idea is to mark the area of conflict between motor vehicles and cyclists so road users pay more attention to this conflict and cyclists have a lane marking through the junction area. Alas, while it is found effectively reducing the number of accidents (and injuries) with one line, it increases it with 2 lines or more, according to [13].

A reason for that is that, it becomes too much solicitation for the motorist than he can process – resulting in an increase of rear ending collisions and red light runnings; and provides a false “sense of safety” to the cyclists, becoming more complacent- not doing head check or using hand signals according to [14]– what is consistent with the “naked street and risk compensation theories.

Supporters of the helmet laws are because they are concerned by the safety of existing cyclists, they will be obviously against separated bike lanes for the same reason. Not surprisingly, most of the anti cyclist lobbyist will fell in this category

Supporter of the helmet laws supporting separated bike lane are not logical with themselves and probably grossly misinformed

Opponent to the helmet laws, will explain that, while the safety of existing cyclists is important, it is not paramount- One have to take a more holistic view to assess the benefit/drawback of such safety tool than the existing cycling population- and opponent to the helmet laws, without necessarily denying the positive safety effect of the helmet on an individual, will oppose to a law on the ground that it discourages sufficiently cycling to have a general negative effect for the society.
Same logic apply to the cycle tracks: there is no need to deny their negative effect on road safety, or to produce biased studies to try to counter evidence, to support them: that is only conductive of complacency with poorly designed cycle tracks which do no good for cycling. Former Vancouver Planning Director, Brent Toderian was able to implicitly recognize the safety issue and supporting it [17]: What is important is to produce evidence that the positive effect they induce outweigh their negative ones

[8] Conclusion of both [4] and [5] are drawn from a study carried from May 2008 to Nov 2009 in Toronto and Vancouver. To the bets of our knowledge, it was no “cycle track” in Toronto, and the only ones able to qualify in Vancouver, were an experiment started on July 2009 on Burrard Bridge, with no intersection along the ~1km cycle track segment, and a ~300m segment in one direction on a quiet street (Carral street) with ~300 cars at peak hour with only one very quiet intersection (Keefer street) featuring ~120 car at peak hour (From City of Vancouver’s 2006 traffic count) what is barely representative of a typical cycle track: The result provided for the cycle tracks is hence certainly irrelevant, and that is the reason it stands as an outlier.

[11] [10] draws conclusion by comparing current crash rate on some cycle tracks with some numbers collected, sometimes in specific situation- like a study on Boston’s bike messengers- more than 10 years ago, without correcting them of external factors, like significant general crashes reduction rate in the last decade, and well documented safety in number effect affecting more particularly the cyclists. Furthermore, one could argue that the “crash rate” is a very poor, if not uncorrelated, proxy, to qualify the safety of a road infrastructure: Roundabout are well-known to increase the rate of crashes, vs a signaled intersection, but they are also well recognized to reduce the risk of serious injuries, most of the crashes being limited to fender-bender type. In other word, a crash rate ratio is not representative of the safety social cost of an infrastructure…what ultimately matter. More awkward [10] suggests that “The AASHTO recommendations may have been influenced by the predominantly male composition (more than 90%) of the report’s authors” without being able to substantiate this assertion, showing that we have here more a opinion paper: attacking the gender of authors to disqualify their works, seems pretty petty at best!

[15] The finding of [13] seems in fact to suggest that the increase in accident and injuries are mainly among motorists, and eventually moped: so that in fact the blue line could effectively be not than “unsafe” for cyclists. Unfortunately, the paper doesn’t provide detailed break down of the injuries according to the transport mode. In any case, the measured global effect is a negative one